Schroth and colleagues recruited pregnant women from an economically disadvantaged urban setting. Serum 25(OH)D levels were measured. One-third were vitamin D deficient although the average serum (OH)D3 concentration (48 nmol/L) of these women would almost be considered sufficient (50 nmol/L). Dental examinations of infants were conducted at 1 year of age. Lower prenatal 25(OH)D3 concentrations were associated with higher early childhood caries and enamel hypoplasia.

My critics will point out that the study was conducted in an economically disadvantaged setting. It is true that this population may be more vulnerable and exhibit greater variability in vitamin D status with more people at the low end of the spectrum than observed in a nationally representative survey. After all, many factors affect vitamin D status – skin pigmentation, clothing, sunscreen use, age, obesity, latitude, season, atmospheric conditions. However, in a population of pregnant women who can be characterized as vitamin D sufficient (on average), there is little doubt that many children face unnecessary developmental risks during the first 1000 days of life.

Personalizing nutrition requires more than meeting an average score. Nutrition needs to be a right for all.